This invention relates to a dust cover for a quick disconnect coupling. "Quick-disconnect" or "breakaway" couplers are devices which allow separation of fluid conducting lines and which further seal both of the separated lines to prevent loss of fluid and also to prevent introduction of foreign material into the fluid system.
The "female" half of the coupler usually incorporates some sort of cavity into which the "male" half is inserted to re-connect the fluid lines. There is also some sort of locking device which maintains the connection. Since the cavity is open to atmosphere when the coupling is disconnected, it is necessary to provide a means of covering or blocking this cavity.
In the past, various types of plugs or covers have been used. This invention was conceived in an effort to provide a simple, dependable method of covering the cavity in the female half of the coupler when the coupler is disconnected. Past devices have fallen into three basic categories.
First were those devices, usually made of rubber or some other plastic material, which cover the open female half of the coupler and which incorporate a slit or flap through which the male half of the coupler is inserted. These are more or less permanently attached to the female coupler half. The rubber or plastic material deteriorates or tears, rendering the closure ineffective. The device accumulates fluid and dust in the area of the slit or flap, and upon insertion of the male half into the closure this accumulation of foreign material is forced ahead of the male half and into the system.
Second were those devices which consist of a metal, rubber, or plastic counterpart of the male half of the coupler (solid and without valving arrangement). These are usually attached to the female half of the coupler by a length of chain, wire or other such restraining method, to prevent loss of the part. These are merely "plugged-into" the female half to prevent introduction of dust and foreign material into the system. These devices are at best clumsy to use as they require the operator to physically and separately plug them into the female half, which he may forget to do. These devices are often lost when a restraining chain or other device is broken. This device also accumulates dust and foreign material as it hangs loose while coupler is connected. This material will be introduced into the system unless it is wiped off.
Third, were those devices similar to this invention, which consist of a pivoted cover, hinged at a location, such that they can be attached to the female half of the coupler and which close automatically upon withdrawal of the male half. Closure is usually by means of a spring arrangement. These devices are mainly ineffective because of misalignment on the face of the female coupler half, thereby leaving an opening through which dirt can enter the system. This is due to te single axis movement of the cover about the hinge pin.
The purpose and object of this invention is to provide an effective, permanent, and automatic means of protecting the system from contamination with sand, dust, and other foreign materials which accumulate at the female half of the coupler due to fluid spilllage at the time of coupler disconnection. This is accomplished in three ways:
1. Permanent attachment to the female half of the coupler. PA1 2. Automatic closure, independent of the initiative and direct actions of the operator. PA1 3. Positive, dust-tight closure due to the unique self-aligning features described below. PA1 U.S. Pat. No. 1,576,712; PA1 U.S. Pat. No. 2,282,532; PA1 U.S. Pat. No. 2,406,563; PA1 U.S. Pat. No. 2,630,131; PA1 U.S. Pat. No. 2,641,485; PA1 U.S. Pat. No. 2,763,459; PA1 U.S. Pat. No. 3,075,547; PA1 U.S. Pat. No. 3,580,414; PA1 U.S. Pat. No. 3,777,926; PA1 U.S. Pat. No. 4,027,696.
According to the invention, a clamping means is mounted on the female half and provides a support for the pivotable cover and the actuating spring therefor. The unique design of the pivoting mechanism of the cover to the clamping means assures that the cover will close tight regardless of alignment due to the fact that this pivoting arrangement is free to move in two mutually perpendicular axes. Another unique feature which contributes to the effective closure of cover is that the actuating spring exerts its entire force directly in the center of the cover, thereby distributing that force equally upon all points of contact between the cover and the face of the female half of the coupler.
A search of the art revealed the following patents, none of which show the above novel combination of elements nor teach the advantages flowing therefrom: